Guns Akimbo is cool. Rifles and shotguns are cool. What could be better than combining them, in the form of handguns that can connect together to form a rifle or shotgun? You can combine your favorite gun tropes together without having to deal with the logistics of a character carrying both types of weapons separately. This also lets a character cover multiple tactical options with much fewer weapons, like handguns for a traditional shootout that can combine into a sniper rifle for long-range engagements.
Sure, Fridge Logic would have you know that Guns Do Not Work That Way: just think of all the firing mechanisms of the forward gun that would somehow have to get out of the way for a bullet fired from the back gun to travel down the barrels of both at once, not to mention the pressure of the firing would likely erupt from where the two barrels connect, which would almost certainly damage the weapon. But, it definitely qualifies for Rule of Cool so these problems may not be a concern.
- Mobile Suit Gundam SEED: The Buster Gundam is equipped with a beam rifle and a railgun, either of which can be powered up by plugging the other gun into its back — the beam rifle becoming a beam Sniper Rifle and the railgun becoming an anti-armor shotgun. In the sequel Mobile Suit Gundam SEED Destiny, the Strike Freedom is equipped with a pair of beam rifles which can combine into a longer rifle in similar fashion.
- In Mobile Suit Gundam 00, the Seravee has two GN Bazookas that can be attached to its Shoulder Cannons for greater range and power, and/or combined together to create a Wave-Motion Gun (which can further transform into a Wave-Motion Tuning Fork mode).
- Great Da Garn GX's signature weapon in The Brave Fighter of Legend Da-Garn. By combining his gatling gun, Ray Gun and Attack Drone, he can form either a longer gatling gun or a Wave-Motion Gun.
- Mobile Suit Gundam Wing: The Wing Zero's signature weapon was the Twin Buster Rifle, a pair of identical cannons that could combine into a single more powerful double-barreled weapon. Each one on its own is basically a MS-sized Wave-Motion Gun powerful enough to obliterate entire space colonies.
- In Tokusou Sentai Dekaranger / Power Rangers S.P.D., the Red Ranger's unique handguns can combine into a single blaster.
- The Man from U.N.C.L.E. gun, or U.N.C.L.E Special. In it's handgun form it resembled a snubnosed Walther P-38, but could be modified into a carbine with barrel extension, pistol scope, an extended magazine and a collapsible shoulder stock.
- Season 4 of Blake's 7 has a rifle that could be broken down into a large handgun. This was originally to be the standard weapon of the (anti)heroes, but they used the Scorpio clipguns instead. The rifle version can be seen in "Warlord" and the handgun version is used in the final episode by Avon to shoot Blake.
- Sazh in Final Fantasy XIII can combine his handguns into a rifle in several of his attacks.
- The Arkham Knight in Batman: Arkham Knight has two handguns that connect into a sniper rifle, which he uses to shoot Batman from longer ranges.
- Xigbar in Kingdom Hearts wields Arrowguns that can connect into a rifle. He avoids the Fridge Logic of how this sort of weapon would work thanks to his Arrowguns using magic projectiles launched from the tips; combining them into a rifle just lets him do a Charged Attack.
- Rufus in Final Fantasy VII Remake swaps out the Sawed-Off Shotgun from the original game for a rifle that can split into two semi-automatic Hand Cannons.
- Super Robot Wars Judgment has the Belzelute's Orgone Rifle: Mode A, where it combines its pistols with its rifle to form a bow-like Wave-Motion Tuning Fork.
- In Call Of Duty Infinite Warfare, the Type-2 assault rifle can be split into dual-wielded machine pistols.
- In Devil May Cry 5, the game features both Lady's original Kalina Ann rocket launcher from DMC3 (which has to be found in the game world) as well as a replica dubbed Kalina Ann II which Nico loans to Dante partway through the story. Obtaining both lets Dante purchase a Gunslinger style move that allows him to combine the two guns end-to-end and fire a large energy beam.